A. wouldn't B. shouldn't C. couldn't D. mustn't

4. You______ park here! It's an emergency exit.

A. wouldn't B. needn't C. couldn't D. mustn't

5. Doctors say that exercise is important for health, but it ______be regular exercise.

A. can B. will C. must D .may

6. The police still haven't found the lost child, but they are doing all they _________ .

A. can B. may C. must D. should

7. Days later, my brother called to say he was all right, but ______ say where he was.

　　A mustn't B. shouldn't C. wouldn't D. mightn't

8. According to the newly-made traffic regulation, whoever drives through red light_________ be fined at least 200 dollars.

A. shall B. may C. would D .should

IV.语法填空：用适当的时态填空

A long ago, there was a woman, 1______ had two children. One was called Tom, and the other was John. One day the woman was very puzzled. She had some cakes in the kitchen but every night of her children2_____eat them. She thought it 3______ be Tom because he was very tall 4_______ John was very shout. But she wasn't sure. The woman had an idea. She put the cakes on a high shelf. The next day , someone 5______(eat) some cakes ."Ah!"said the woman. It 6_______be John .He's too short! It7______be Tom! She was very angry with Tom, 8______ (think) , "He9______be punished for what he had done!"Poor Tom. In fact, he hadn't eaten the cakes. I t was John .How? Can you guess? Yes, he10______have used a chair!